Dan,
I would be cautious about accepting a dealer's "recommendations". While in some cars periodic cleaning of the throttle butterfly is beneficial, I don't think Acura recommends it. Look in the service schedule for your RDX, or, if it has a Maintenance Minder (in-car reminder), ask the dealer when the service code will typically show up. I bet it won't.
You have to be careful with Honda throttle bodies anyway because the throttle position sensors are riveted on, and a cleaner may damage them... and the throttle body assembly ain't cheap.:run: